Microbial communities and tight junction protein expression in the gastrointestinal tract of feedlot cattle
Bibliographic record
Abstract
The gastrointestinal tract (GIT) of cattle plays a vital role in nutrient absorption, immune function, and microbial homeostasis. While the importance of the GIT microbiome and epithelial barrier integrity has been increasingly recognized, the typical composition of microbial communities and the expression of tight junction proteins (TJPs) in feedlot cattle remains poorly characterized. We investigated microbial community structure and TJP expression at three GIT sites: the rumen (RU), small intestine (SI), and large intestine (LI) in 21 finish-fed feedlot steers sourced from 21 commercial feedyards in the Texas Panhandle. Samples of luminal contents and GIT tissue were collected from each region, as well as feces and liver abscess material. Microbial communities were characterized using 16S rRNA gene sequencing. TJP gene expression was quantified by RT-qPCR using synthetic standards, and protein expression was evaluated by immunohistochemistry (IHC) with both computer-generated and pathologist-generated scoring. Microbial community structures varied primarily by GIT region rather than by individual animals raised at different locations. Nine bacterial families were identified as core microbiome members, with Lachnospiraceae being the most abundant across the GIT. TJP gene expression varied considerably by site, with RU having significantly lower Claudin 1, Claudin 2, and E-Cadherin expression than the SI and LI. IHC results paralleled qPCR findings, with region-specific patterns of protein localization and intensity. Computerized and pathologist-generated H-scores showed moderate agreement but differed notably between epithelial and lamina propria regions. This study provides a comprehensive baseline of microbial and host factors associated with gut health in a uniquely diverse population of feedlot cattle. The identification of regional microbial communities and distinct TJP expression patterns offers foundational insights into gastrointestinal physiology and barrier function. This work establishes baseline data to support future investigations into the relationships among microbial ecology, epithelial barrier function, and cattle health and productivity.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".